Through the Environmental Protection Agency (EPA), the federal government regulates the quality of tap water provided by utilities. The regulations set water quality standards that limit the level of chemical contaminants found in the water. The EPA sets those standards based on the level they consider to be safe.
However, an organization called the Environmental Working Group (EWG) developed a different set of standards based on the level of chemical contaminants in the water that pose no health risk, so the EWG’s standards are stricter than the EPA’s. The EWG argues that the EPA standards are dated. The EPA standards have not kept up with new research regarding chemical contaminants that cause harm and have not added new contaminants to their standards.
It is unclear whether the EPA’s standards account for factors such as the cost of removing chemicals to a level that poses no risk. These could include the costs of updating the filtration system to remove the contaminants and the ongoing operating costs to maintain the system. In addition to developing the standards, the EWG created a searchable database for people to enter their ZIP code to see how the EWG rates tap water quality supplied by their utility. Individuals concerned about the contaminants can add a home filter designed to remove the impurities of concern.